Direct Url not opening through firebase function

Everything seems to be working. I can view the Angular App through my firebase hosting url. But: As soon as I call a route directly e.g. I get this error (copied from firebase functions log)

TypeError: handler is not a function
at cloudFunction (/srv/nodemodules/firebase-functions/lib/providers/https.js9)
at /worker/worker.js7
at /worker/worker.js11
at ZoneDelegate.invokeTask (/srv/dist/server.js31)
at Zone.runTask (/srv/dist/server.js47)
at ZoneTask.invokeTask (/srv/dist/server.js34)
at ZoneTask.invoke (/srv/dist/server.js48)
at data.args.(anonymous function) (/srv/dist/server.js25)
at combinedTickCallback (internal/process/nexttick.js7)
at process.tickDomainCallback (internal/process/nexttick.js9)

Live Url: